Adverse drug events (ADEs) which are caused by the administration to a patient of intravenous medications of incorrect types, concentrations or dosages may cause irreparable damage or even death in a patient. These types of ADE are entirely preventable and attempts have been made to minimise or avoid their occurrence. An example ADE prevention system is disclosed in U.S. Pat. No. 6,847,899B. In this document plastic tubing forming part of an IV administration set between an IV bag containing a drug to be administered and a needle in a patient's arm is passed through a spectroscopic analyser. The analyser is capable of determining both the type of drug present in the tubing and its concentration. A comparison may be made with expected results from the intended drug type and concentration and a decision made on whether to allow an infusion to continue.
In the above described system, variation in the positioning of the tubing within the spectroscopic analyser and variation in the physical and optical properties of the tubing itself will affect the outcome of the analysis. Furthermore, an IV administration set is often used to transport more than one type of drug, at different times, to the patient. Contamination of the tubing with multiple drug types reduces the ability of the spectroscopic analyser to determine the type of drug currently present.